The requirement of authentication or identification as a condition precedent to admissibility is satisfied by evidence sufficient to support a finding that the matter in question is what its proponent claims.

In other words, before an alleged confession note written by the defendant can be admitted, the proponent of the note must present some evidence establishing that the note was indeed written by the defendant. And if the defendant wants to introduce what he claims is a tape recording of the alleged victim's mother yelling at her, he must present some evidence establishing that it is indeed the mother's voice on the tape. In Sosa v. State, 2010 WL 2330304 (Tex.App.-Austin 2010), this was something that the defendant was unable to do.

In Sosa, Teodoro Sosa was convicted of indecency with a child by contact based upon an improper touching that he allegedly committed against his niece, K.F., who was staying with her family at Sosa's house.

At trial, defense counsel attempted to introduce an audio cassette tape that allegedly contained a recording of [K.F.'s mother] E.F. screaming at K.F. and calling her derogatory names. The defense's theory was that K.F. lied about the touching because she was angry with Sosa, and then remained committed to her original story because she was afraid to tell her mother that she had lied. After both K.F. and E.F. testified that K.F. had a good relationship with her mother and was not afraid of her, the defense sought to admit the tape recording as impeachment evidence. The tape was played outside the presence of the jury, and E.F. denied that it was her voice on the recording. The trial court excluded the tape on the grounds that it was not properly authenticated and that its probative value was outweighed by the risk of unfair prejudice.

After Sosa was convicted, he appealed, claiming, inter alia, that the trial court erred by precluding him from admitting this cassette tape. The Court of Appeals of Texas, Austin disagreed, first finding that Sosa never properly authenticated the tape. Instead,

E.F. denied that the voice on the tape was hers, and Sosa presented no evidence to the contrary. Furthermore, Sosa produced no evidence as to how, when, or by whom the tape was made. As the trial court stated in excluding the evidence, "[T]here is no offering witness that...anybody has offered to testify as to any of the circumstances concerning the making of the tape, who made it, when it was made, under what circumstances it was made, whether it was accurately made, whether it was pieced together or whether it was just one conversation." Given the lack of evidence that the tape was in fact what Sosa claimed it to be, we hold that the trial court acted within its discretion in determining that the recording's authenticity had not been sufficiently established to allow its admission into evidence.

Moreover, the appellate court agreed with the trial court that even if the tape had been authenticated, it would have been excluded because its probative value was substantially outweighed by the danger of unfair prejudice. Specifically, the court found that

Allowing the jury to hear a tape recording of someone, allegedly K.F., yelling at her young daughter and calling her derogatory names, including racial slurs, presented a significant risk of unfair prejudice and confusion of issues. The probative value of the recording was limited, as it was offered in support of Sosa's theory that K.F. was afraid to tell her mother that she had lied about the sexual abuse. The trial court had already permitted the defense to explore this issue in other testimony, as both Sosa and his wife were allowed to testify that E.F. frequently mistreated K.F. by yelling at her and calling her names.